Answer to Question #5156 Submitted to "Ask the Experts"

Is there a somewhat universally or consensus accepted method to determine uranium enrichment using isotopic analytical data and, if so, what is the preferred analytical method?

Uranium enrichment—that is, the fraction by weight of ²³⁵U—can be determined by direct alpha spectrometry, mass spectrometry, and evaluation of fission-product activity following slow neutron bombardment in a reactor. Chemical separation is usually required beforehand. Of these three methods, mass spectrometry gives the best results, but is time consuming and expensive and limited in that most labs do not have a mass spectrometer available to them. Similarly, neutron bombardment requires a reactor, which again is not commonly available. So it would seem that economics and other considerations make direct alpha spectrometry, which virtually any radiochemistry laboratory has the capability to perform, the preferred method.

Ronald Kathren, CHP